Energy and water co-benefits from covering canals with solar panels
Data files
Jan 29, 2021 version files 78.37 MB
Abstract
In the manuscript entitled, "Energy and water co-benefits from covering canals with solar panels", we quantified the evaporation savings and financial performance of over-canal solar in comparison to over-ground solar on land adjacent to canals, using regional-scale hydrologic and cost simulations. We conducted regional hydrologic and techno-economic simulations of solar PV panels covering California’s 6350 km canal network. We examined the net effect on the financial performance of three different solar PV structures at eight different sites along the California network of canals. The three solar PV structures included a ground-mounted system, a steel-truss canal-spanning design that has been deployed in Gujarat, India, and a suspension-cable canal-spanning design that has been deployed in Punjab, India. Our financial performance includes the net present value (NPV) and the levelized costs of energy (LCOE) comparisons of over-canal to ground-mounted designs considered enhanced PV performance due to evaporative cooling, and avoided costs for water and aquatic weed mitigation. Here, we provide the additional supporting information (Appendices A, B, and C) and the data we used to generate Figures 1, 3, and 4 in the main manuscript.
Methods
Appendix A
We used the National Renewable Energy Laboratory's System Advisor Model (SAM) software (v. 2017.9.5) to conduct a techno-economic comparison of ground-mounted and over-canal solar PV systems. Here, we include the inputs to and the outputs from SAM as supplementary datasets. Appendix A1 includes screenshots of the inputs to SAM including location and resource, module selection, inverter selection, system design, shading and snow, losses, lifetime, battery storage, system costs, financial parameters, time of delivery factors, incentives, and depreciation. Appendix A2 includes the NPV and LCOE outputs. Appendix A3 includes the SAM outputs used in the sensitivity analysis. The workbook entitled "Edmonston_Sensitivity_Analysis.xlsx" includes the sensitivity analysis of the NPV of the suspension-cable design at the Edmonston Pumping Plant location. Here, we considered the parameters that contributed most to the variance in the standard deviations of our main results and the impact of alternative parameters that were not included in our main results. The workbook entitled "Edmonston_Alternative_SAM_Financial_Models.xlsx" compares the results of the ground-mounted system to the tensioned-cable system for the Edmonston Pumping Plant considering alternative financing approaches available in SAM and two federal subsidy rates (ITC of 22% and 10%). The alternative financing approaches include commercial, utility-scale PPA partnership flip with debt, utility-scale PPA partnership flip without debt, and utility-scale PPA sale-leaseback.
Appendix B
We fitted the distributions of our outputs from SAM with EasyFit Professional software (v. 5.6). Using the best fit distribution, determined with Kolmogorov-Smirnoff statistics, we% ran Monte Carlo simulations of 10000 samples. Here, we include the inputs to and outputs from EasyFit as supplementary datasets. Appendix B includes the screenshots of the distributions of the NPV and LCOE as inputs, screenshots of the probability distribution functions, the goodness of fit summaries, summaries of the fitting results (e.g. fitting parameters), and the output of the random number generator (Monte-Carlo simulation).
Appendix C
We ran a percentile bootstrap analysis of 1000 replicates of the sample medians to estimate the 95% confidence intervals using the boot package in RStudio (v. 1.2.5033). Here, we include the inputs to and outputs from RStudio as supplementary datasets. Appendix C1 includes the Monte Carlo samples as inputs. Appendix C2 includes RStudio used to conduct the bootstrap analysis and the results (median and 95% confidence interval).
Usage notes
The attached appendices and supporting data for the figures in the main manuscript are provided to ensure the reproducibility of our study. There are no missing values in the input files.